Abstract

Waste-activated sludge (WAS) processes are key technologies to treat wastewater: their effluents can meet stringent discharge standards, thus ensuring a minimum residual impact on the aquatic environment. The presence of heavy metals in the excess sludge poses, however, serious problems, and considerably hampers the final disposal alternatives, especially in the agricultural use (soil improvement/amendment). This article studies the effect of thermal hydrolysis and Fenton's peroxidation on the heavy metal content of the dewatered sludge. Acid thermal hydrolysis reduces the heavy metal content in the filter cake except for Cu, Hg, and Pb. Alkaline thermal hydrolysis releases Cu, Pb, and Cr. Fenton's peroxidation transfers Cd, Cu, and Ni from the filter cake into the filtrate. Land application of the residual cake can hence be reconsidered.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.